(University of Cape Town, Museum of Nature and Temple University press release, 11 April 2012) -- Duck-billed dinosaurs that lived within Arctic latitudes approximately 70 million years ago likely endured long, dark polar winters instead of migrating to more southern latitudes, a recent study by researchers from the University of Cape Town, Museum of Nature and Science in Dallas and Temple University has found.

The researchers published their findings, "Hadrosaurs Were Perennial Polar Residents," in the April issue of the journal The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology. Anthony Fiorillo, a paleontologist at the Museum of Nature and Science, excavated Cretaceous Period fossils along Alaska's North Slope. Most of the bones belonged to Edmontosaurus, a duck-billed herbivore, but some others such as the horned dinosaur Pachyrhinosaurus were also found.

Fiorillo hypothesized that the microscopic structures of the dinosaurs' bones could show how they lived in polar regions. He enlisted the help of Allison Tumarkin-Deratzian, an assistant professor of earth and environmental science, who had both expertise and the facilities to create and analyze thin layers of the dinosaurs' bone microstructure. Another researcher, Anusuya Chinsamy-Turan, a professor of zoology at the University of Cape Town, was independently pursuing the same analysis of Alaskan Edmontosaurus fossils. ...

What the researchers found was bands of fast growth and slower growth that seemed to indicate a pattern. "What we found was that periodically, throughout their life, these dinosaurs were switching how fast they were growing," said Tumarkin-Deratzian. "We interpreted this as potentially a seasonal pattern because we know in modern animals these types of shifts can be induced by changes in nutrition. But that shift is often driven by changes in seasonality."

Tagged: Arctic, News, Polar research: Reports and findings

(Debra Black/Toronto Star, 11 April 2012) -- A polar bear expert and professor of biological sciences at the University of Alberta is critical of the “spin” put on a recent aerial survey of polar bears in the western Hudson Bay. The study, which was conducted on behalf of the Nunavut government, found that there are likely about 1,013 polar bears in the region, which is not significantly different from a previous mark-and-recapture or tagging study done in 2004. This has led some to conclude that the polar bear population hasn’t significantly declined over the last seven years, despite the predictions of some scientists who have suggested that the population would decline to about 650 by 2011.

But Andrew Derocher, who has studied polar bears for 40 years, believes that the two surveys can’t be compared. “It’s like comparing apples and oranges,” he explained to the Star in a phone interview. The aerial study looked at a much larger region than the tagging study, Derocher said. “Effectively you can’t compare the abundance between the mark-and-recapture survey and the aerial survey directly because they’re measuring two different things.” Derocher believes the Nunavut Tunngavik Inc. — a company formed to advance the rights of the Nunavut land rights agreement, including the harvesting rights of the Inuit — may have “jumped the gun rather than waiting for a complete analysis” of the survey.

Tagged: News, Research